Separation of Dipeptides with Two Chiral Centers Using 2-hydroxypropyl-beta-CD-modified MEKC

A method was developed for the chiral separation of dipeptides with two chiral centers. Although all analyzed peptides contain chromophores and they can be detected by UV-adsorption detection without any derivatization, the chiral separations were not achieved for non-derivatized peptides using the same chiral selectors and experimental conditions. In this paper, these dipeptides were precolumn derivatized by using naphthalene-2, 3-dicarboxyaldehyde as a tagging reagent. In the presence of 2-hydroxypropyl-beta-CD and sodium deoxycholate, naphthalene-2,3-dicarboxyaldehyde-tagged dipeptide enantiomers were well resolved by MEKC. Good separation of all enantiomers was obtained within 14 min. The proposed method was applied to chiral separation of dipeptide enantiomers in spiked human serum samples.